I personally don't think falco is a worse character, but the better one. (I dual main the spacies, but mostly falco)
IMO:
Falco has a less dominant matchup spread in general, but he is equal at worst in all his matchups. When played correctly, he might even be slightly better to very advantageous in all his matchups.
Fox has been more controversial in his matchups spread namely against falco/marth for which perceptions have ranged drastically. My opinion of the neutral/risk/punishment game is that it favors marth and falco slightly which is a large factor why I dont solo/mostly use fox even though I find him kinda fun.
I think theres a lot of factors, some subtle that really affect situations where each character has strengths and advatanges. Some examples:
fox has a shorter jump squat and peak height
falco has longer techrolls
fox's shine has a bigger hitbox
falco's shine has I think minimum 50-55 frames stun (jiggs) and then longer on other chars.
falco's limbs reach slightly longer and his bair autocancels on shorthop
foxes nair and bair are slightly stronger.
falcos side b is faster and with his dj gives him better short ranged recovery mixups
fox's long range recovery is generally better.
fox's upthrow generally is more reliable for following up.
I could go on for paragraphs because there are so many...
If I had to loosely generalize all these differences between these versatile and very different characters with different playstyles into why one is better, I would say falco is better due to having more practically reliable and stronger punishes on average while also having a better neutral game because of his toolset. This is what I observe in practice and in the current metagame. There are all sorts of hypotheticals that might spiral into this counters that arguments which are pretty much endless until we get into a somewhat meaningless conclusions about shines and parries and powershields and counter powershields and bowser's up b. Almost all combos and options have counters and aren't truly reliable especially at the human level of consistency and reaction time, so I am giving my opinion on what I believe is the practical level in the current metagame.
I don't really want to get too much into this as it is again, a somewhat endless this counters that situation, but some people might have the perception that powershielding lasers counters falco to a huge degree. Just like one of falco's most favorable interaction with the laser is him shooting you with it and getting a punish, one of foxes would be powersheilding and jumping/wdoos or having it hit falco. Theres so many different ways that both characters interact with shooting lasers and powershielding lasers and dealing with lasers in general, that its really not that simple as fox is put in an awful postion by lasers or falco is put in an awful position by a laser being powershielded.
Though my (loose) opinion is given based on my observation of the two characters in the current metagame, I don't know what the future will hold for our spacie heroes. These characters have so much potential and theres so many factors that its really hard to even form an opinion other than "theres too many factors."